JP2002308987A - Method and apparatus for producing polyarylene sulfide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polyarylene sulfide(PAS) wherein the compositional ratio of the polymer to the solvent can be more precisely controlled by forming a uniformly dispersed polymer phase in a PAS polymerizer, and to provide an apparatus for producing a PAS wherein the compositional ratio of the polymer to the solvent can be more precisely controlled by forming a uniformly dispersed polymer phase in a PAS polymerizer. SOLUTION: The method is the one for producing the polyarylene sulfide by forming a polyarylene sulfide in a polymerizer and separating the reaction mixture into a polymer phase and a solvent phase, wherein the polymer phase is discharged from a discharge port provided in the end plate of the polymerizer. The apparatus is the one used for producing the polyarylene sulfide and having a polymerizer equipped with an agitating blade, wherein the discharge port provided in the end plate of the polymerizer and projecting into the polymerizer to a length corresponding to 0-80% of the clearance between the tip of the blade and the bottom on the polymerizer is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyarylene sulfide and an apparatus for producing the same, and more particularly, to a method for separating a polymer phase and a solvent phase in producing a polyarylene sulfide. The present invention relates to a method for producing a polyarylene sulfide capable of forming a uniform dispersion state and an apparatus for producing the same.

[0002]

2. Description of the Related Art Polyarylene sulfide (hereinafter referred to as PA)
S), among which polyphenylene sulfide is known as an engineering plastic having excellent mechanical strength and heat resistance, as well as good electrical properties and high rigidity. Widely used as various materials. In recent years, as a method for producing a polyarylene sulfide having a high molecular weight, many methods for performing polymerization using a phase separator have been proposed. In such a method, the polymer phase and the solvent phase are separated from each other in the polymerization tank after the polymerization reaction, and at that time, at the bottom of the tank where the shearing force due to stirring is difficult and the polymer phase settles due to a difference in specific gravity, Depending on the position, a remarkable composition distribution of the polymer and the solvent sometimes occurred. As described above, in order to obtain a PAS having a high molecular weight, it is usually necessary to keep the composition ratio of the polymer and the solvent in the polymerization tank constant. Therefore, as one method, it is conceivable to extract the polymer phase and the solvent phase together from near the center in the depth direction of the polymerization tank, which is considered to be in an average stirring state in the tank. In Japanese Patent Application Laid-Open No. 9-169844, a reservoir is provided at the bottom of a polymerization tank, and a polymer phase is extracted therefrom. On the other hand, a solvent stagnation section is provided from the top of the polymerization tank, and the solvent phase has a constant composition ratio. There is disclosed a method of extracting so that

[0003]

However, even in the above-mentioned method, the uniformity of the dispersed state of the polymer phase is still insufficient, so that the dispersed state is further homogenized and the composition ratio of the polymer and the solvent is more precisely determined. There has been a demand for a method of controlling well, and a method capable of producing PAS with a simple apparatus without providing a special stagnant portion as disclosed in the above publication. The present invention has been made in view of the above-mentioned problems, and a PA capable of forming a uniform dispersion state of a polymer phase in a PAS polymerization tank and controlling the composition ratio of a polymer and a solvent more accurately.
An object of the present invention is to provide a method for producing S and a PAS production apparatus capable of forming a uniform dispersion state with simple specifications and controlling the composition ratio of the polymer and the solvent with higher accuracy.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above problems, and as a result, after polymerizing polyarylene sulfide to separate it into a polymer phase and a solvent phase, the polymer sediments at the bottom of the polymerization tank. It has been found that the above object of the present invention can be achieved by immediately extracting at least a part of the polymer phase and preventing the polymer phase from agglomerating. The present invention has been completed based on such findings. That is, the present invention provides a method for producing a polyarylene sulfide in which a polyarylene sulfide is polymerized in a polymerization tank and separated into a polymer phase and a solvent phase, wherein the polymer phase is extracted from an extraction portion provided on a head plate of the polymerization tank. In the method for producing a polyarylene sulfide, and a polyarylene sulfide production apparatus having a polymerization tank provided with a stirring blade, the gap distance between the tip of the stirring blade and the bottom of the polymerization tank is provided on the end plate of the polymerization tank The present invention provides an apparatus for producing a polyarylene sulfide, comprising a withdrawing portion protruding into a polymerization tank with a length of 0 to 80% of the above.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The production of the polyarylene sulfide of the present invention is carried out by polycondensing a sulfur source and a dihalogenated aromatic compound in an organic polar solvent in the presence of a phase separating agent as necessary. Examples of the sulfur source used in the production method of the present invention include alkali metal sulfides, alkali metal hydrosulfides, and hydrogen sulfide. As the alkali metal sulfide, specifically,
Examples include lithium sulfide, sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide. Among these, lithium sulfide and sodium sulfide are preferable, and lithium sulfide is particularly preferable. These may be used alone or in combination of two or more. Further, as the alkali metal sulfide, one obtained by reacting an alkali metal hydrosulfide with a base may be used. Alternatively, an alkali metal hydrosulfide and a base can be used together with the alkali metal sulfide. Furthermore, hydrogen sulfide and a base can be used together as a sulfur source, and hydrogen sulfide and a base can be used together with an alkali metal sulfide and / or an alkali metal hydrosulfide. Alkali metal hydrosulfides include lithium bisulfide, sodium bisulfide,
Examples thereof include rubidium hydrosulfide, potassium bisulfide, and cesium hydrosulfide. Of these, lithium bisulfide and sodium bisulfide are preferred, and lithium bisulfide is particularly preferred. These may be used alone or in combination of two or more.

As the base, one capable of converting the alkali metal hydrosulfide to the alkali metal sulfide, one capable of converting the hydrogen sulfide to the alkali metal hydrosulfide, or the alkali metal hydrosulfide or the hydrogen sulfide is used. It is possible to efficiently neutralize or accept hydrogen halide that can be generated by condensation with a dihalogenated aromatic compound described below, and if it is an acid acceptor that does not inhibit the object of the present invention, it is an inorganic compound. May be an organic compound, and various bases can be used. Usually, an alkali metal hydroxide or the like is preferably used. Specific examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. Of these, lithium hydroxide and sodium hydroxide are preferred, and lithium hydroxide is particularly preferred. As the salt of the organic compound, a metal salt of ω-hydroxycarboxylic acid, a metal salt of aminocarboxylic acid, and the like can be preferably used. These bases may be used alone or in combination of two or more. Further, the use ratio of the base is usually about 0.80 to 1.2 mol per 1 mol of the total hydrogen atoms of the alkali metal hydrosulfide and the hydrogen sulfide. As the alkali metal sulfide and the alkali metal hydrosulfide, an industrial product having 2.6 to 9 moles of water of hydration with respect to 1 mole thereof may be used after being dehydrated in advance, or may be used as it is. Good.

As the dihalogenated aromatic compound used in the method of the present invention, there may be mentioned known compounds used for producing polyarylene sulfide. For example, dihalobenzenes such as p-dihalobenzene and m-dihalobenzene; 2,3-dihalotoluene, 2,5-dihalotoluene, 2,6-dihalotoluene, 3,4-dihalotoluene, 2,5-dihaloxylene, 1-ethyl-2, 5-dihalobenzene, 1,2,4,5-tetramethyl-3,6
Alkyl-substituted dihalobenzenes such as -dihalobenzene, 1-normalhexyl-2,5-dihalobenzene, 1-cyclohexyl-2,5-dihalobenzene or cycloalkyl-substituted dihalobenzenes; 1-phenyl-2,5
Aryl-substituted dihalobenzenes such as -dihalobenzene, 1-benzyl-2,5-dihalobenzene, 1-p-tolyl-2,5-dihalobenzene; dihalobiphenyls such as 4,4'-dihalobiphenyl; And dihalonaphthalenes such as dihalonaphthalene, 1,5-dihalonaphthalene, and 2,6-dihalonaphthalene.

The amount of the dihalogenated aromatic compound to be used is usually 0.90 to 1.30 mol per 1 mol of the sulfur atom in the sulfur source when no later-described branching agent is used.
Preferably it is 0.95 to 1.20 mol. When a branching agent is used, the total number of moles of the dihalogenated aromatic compound and the branching agent is usually 0.1 mol per mol of the sulfur atom in the sulfur source.
It is 90 to 1.30 mol, preferably 0.95 to 1.20 mol. Examples of the phase separator used in the present invention include lithium halides such as lithium chloride and lithium fluoride; alkali metal acetates such as lithium acetate and sodium acetate; alkali metal sulfonates such as lithium sulfonate and sodium sulfonate; and water. And the like. Among them, lithium halide, alkali metal acetate and water are preferred. The amount of the phase separator used is not particularly limited as long as the amount of the polymer phase is generated, and is usually 0.05 to 3.0 mol, preferably 1 to 3 mol, per 1 mol of the sulfur atom in the sulfur source. Is 0.2 to 2.5 mol. If the amount of the phase separation agent is less than 0.05, the effect of adding the phase separation agent is not sufficient,
The reaction rate may be slow, or the PAS obtained may not be sufficiently high in molecular weight or highly purified. On the other hand, if the amount of the phase separator exceeds 3.0 moles, no effect commensurate with the amount used can be obtained, the production cost increases, and it is not economical.

In the present invention, together with the phase separating agent,
If necessary, an active hydrogen-containing halogenated aromatic compound,
A branching agent such as a polyhalogenated aromatic compound and a halogenated aromatic nitro compound having three or more halogen atoms in 1 can be appropriately selected and added to the reaction system. As the active hydrogen-containing halogenated aromatic compound,
Examples thereof include halogenated aromatic compounds having a functional group having active hydrogen such as an amino group, a thiol group, and a hydroxyl group. More specifically, 2,6-dichloroaniline, 2,5-dichloroaniline, Dihaloanilines such as 2,4-dichloroaniline and 2,3-dichloroaniline; 2,3,4-trichloroaniline, 2,3;
Trihaloanilines such as 5, -trichloroaniline, 2,4,6-trichloroaniline, 3,4,5-trichloroaniline; 2,2′-diamino-4,4′-dichlorodiphenyl ether, 2,4′-diamino Examples include dihaloaminodiphenyl ethers such as -2 ', 4-dichlorodiphenyl ether and compounds in which an amino group is replaced with a thiol group or a hydroxyl group in these compounds. Further, in these active hydrogen-containing halogenated aromatic compounds, active hydrogen in which a hydrogen atom bonded to a carbon atom forming an aromatic ring is substituted with another inert group, for example, a hydrocarbon group such as an alkyl group. Included halogenated aromatic compounds can also be used. Among these various active hydrogen-containing halogenated aromatic compounds, preferred are active hydrogen-containing dihalogenated aromatic compounds, and particularly preferred is dichloroaniline.

The polyhalogenated aromatic compound having three or more halogen atoms in one molecule includes, for example, 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,4,6- Trichloronaphthalene and the like. Examples of the halogenated aromatic nitro compound include monohalonitrobenzenes such as 2,4-dinitrochlorobenzene; dihalonitrobenzenes such as 2,5-dichloronitrobenzene; 2-nitro-4,4′-
Dihalonitrodiphenylethers such as dichlorodiphenylether; dihalonitrodiphenylsulfones such as 3,3'-dinitro-4,4'-dichlorodiphenylsulfone; monohalonitropyridines such as 2-chloro-3,5-dinitropyridine And dihalonitropyridines such as 2,5-dichloro-3-nitropyridine and various dihalonitronaphthalenes. By using these active hydrogen-containing halogenated aromatic compounds, polyhalogenated aromatic compounds and halogenated aromatic nitro compounds, it is possible to increase the degree of branching of the produced polymer, further increase the molecular weight, The properties of the polymer formed by the method of the present invention can be further improved, for example, by forming a gel-forming polymer having reduced melt fluidity. In the method of the present invention, one of these branching agents may be used alone, or two or more thereof may be used in combination. The amount of the branching agent is usually 0.0005 to 0.05 mol per mol of the sulfur atom in the sulfur source,
Preferably it is 0.001-0.02 mol.

As the organic polar solvent used in the present invention, aprotic polar organic compounds (for example, amide compounds, lactam compounds, urea compounds, organic sulfur compounds,
Cyclic organic phosphorus compounds) can be suitably used as a single solvent or as a mixed solvent. Among these aprotic polar organic compounds, the amide compound includes, for example, N, N-dimethylformamide, N, N
-Diethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dipropylacetamide, N, N-dimethylbenzoamide.

The lactam compounds include, for example, caprolactam, N-methylcaprolactam, N-
N-alkylcaprolactams such as ethylcaprolactam, N-isopropylcaprolactam, N-isobutylcaprolactam, N-normalpropylcaprolactam, N-normalbutylcaprolactam, N-cyclohexylcaprolactam, N-methyl-2-pyrrolidone (N
MP), N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-isobutyl-2-pyrrolidone, N-n-propyl-2-pyrrolidone, N-n-butyl-2-pyrrolidone, N-cyclohexyl-2
-Pyrrolidone, N-methyl-3-methyl-2-pyrrolidone, N-ethyl-3-methyl-2-pyrrolidone, N-methyl-3,4,5-trimethyl-2-pyrrolidone, N-
Methyl-2-piperidone, N-ethyl-2-piperidone, N-isopropyl-2-piperidone, N-methyl-
6-methyl-2-piperidone, N-methyl-3-ethyl-2-piperidone and the like can be mentioned.

The urea compound includes, for example,
Tetramethyl urea, N, N'-dimethylethylene urea,
N, N'-dimethylpropylene urea and the like can be mentioned. Further, as the organic sulfur compound, for example, dimethyl sulfoxide, diethyl sulfoxide, diphenyl sulfone, 1-methyl-1-oxosulfolane, 1-ethyl-1-oxosulfolane, 1-phenyl-1-oxosulfolane, and the like, Examples of the cyclic organic phosphorus compound include 1-methyl-1-oxophosphorane, 1-n-propyl-1-oxophosphorane, 1-phenyl-1-oxophosphorane, and the like. These various aprotic polar organic compounds, each alone or by mixing two or more,
Furthermore, it can be used as an organic polar solvent by mixing with other solvent components that do not interfere with the object of the present invention. Among the various aprotic organic solvents, preferred are N-alkylcaprolactam and N-alkylpyrrolidone, and particularly preferred is N-methyl-2-pyrrolidone. The amount of the organic polar solvent to be used is generally 1 to 30 mol, preferably 3 to 15 mol, per 1 mol of the sulfur atom in the sulfur source.

In the present invention, the polymerization reaction is carried out at 230 to 29.
0 ° C., preferably 240-280 ° C., more preferably 2 ° C.
The reaction may be carried out in a single-stage reaction at 50 to 270 ° C, but before the polycondensation, 180 to 230 ° C, preferably 190 to 230 ° C.
It is preferable to carry out the prepolymerization at 20 ° C, more preferably at 195 to 215 ° C. The reaction time of the polycondensation is 0.5 to 10
Hours, preferably 1.0 to 10 hours, more preferably 1.5 hours
10 hours. In the production method of the present invention, in the polymerization tank, when polymerizing polyarylene sulfide by the polymerization reaction and separating into a polymer phase and a solvent phase, an extraction part is provided on the end plate of the polymerization tank, and the polymer phase is separated from the extraction part. It is characterized by being extracted. In the present invention, the term “end plate” refers to a plate portion such as a dish plate that constitutes an end of a body portion in a polymerization tank. In the method or apparatus of the present invention, the position of the polymer phase extraction portion is not particularly limited as long as it is located in the end plate portion, but from the viewpoint of the effect of the present invention, the bottom of the polymerization tank,
In particular, it is preferable to provide it at the bottom.

In the present invention, the provision of the extraction portion in the end plate as described above makes it possible to immediately extract at least a portion of the polymer phase settling at the lower portion of the polymerization tank from the end portion, thereby preventing the settling polymer phase from agglomerating. it can. FIG. 1 is a schematic cross-sectional view showing an example of a PAS manufacturing apparatus according to the present invention. FIGS. 1A and 1B are examples in which an extraction portion is provided at the bottom, and B denotes an polymerization tank. It is an example of the one that protrudes inward. According to FIG. 1, in a polymerization tank 1 provided with a stirring blade 2 and a baffle 3, an extraction part 5 is provided in a bottom end plate 4.

In particular, in the method and apparatus of the present invention,
As can be seen in FIG. 1B, the extraction portion preferably has a shape in which the position of the extraction port protrudes from the polymerization tank bottom end plate 4 into the polymerization tank. It is preferable to use one having a length of 80% or less of the distance between the tip and the bottom of the polymerization tank and projecting from the bottom plate 4 at the bottom of the polymerization tank into the polymerization tank. By doing so, the control of the composition ratio between the polymer phase and the solvent phase in the polymerization tank becomes easy at the same time as preventing the agglomeration of the polymer phase, which is extremely preferable in terms of increasing the molecular weight of PAS. If the above value exceeds 80%, structural drawbacks such as contact of the extraction portion with the stirring blade may occur. From the above points, it is more preferable that the position of the outlet is in the range of 50 to 70% of the gap distance between the tip of the stirring blade 2 and the bottom of the polymerization tank.

In the present invention, the shape, size, material and the like of the extraction portion are not particularly limited except for the above points.
In the production of S, it can be appropriately determined according to the production scale, the stirrer specifications, and the like. For example, a commercially available steel pipe or the like can be used. In the present invention, after the polycondensation of a sulfur source and a dihalogen aromatic compound in an organic polar solvent in an organic polar solvent under stirring by a stirring blade 2 in the presence of a phase separating agent as necessary, separation is performed. The polymer phase settled to the lower part due to the difference in specific gravity among the solvent phase and the polymer phase is extracted from the extraction part 5 provided on the bottom plate 4 of the polymerization tank,
Prevents the settling of the polymer phase from clumping.

[0018]

EXAMPLES The present invention will be described more specifically with reference to the following examples. Example 1 554 kg of N-methyl-2-pyrrolidone (NMP) and 100 kg (2.38 mmol) of lithium hydroxide (LiOH.H ₂ O) were charged into a 1 m ³ titanium raw material synthesizing tank equipped with a prepolymerization stirrer, and then raised. While maintaining the temperature at 140 ° C., water contained in the raw material lithium hydroxide was removed by batch distillation. Next, while maintaining the temperature at 130 ° C., gaseous hydrogen sulfide was
A kiloliter of lithium hydrosulfide was synthesized. Thereafter, the injection of hydrogen sulfide was stopped, and the polymerization tank was again set at 205
The temperature was raised to ° C. With the increase in temperature, water produced as a by-product when hydrogen sulfide was blown was removed by batch distillation, and lithium sulfide was formed from lithium hydrosulfide. After the reaction,
The reaction mass contained 1.08 mmol of lithium sulfide and N-
It contained 0.214 mmol of lithium methylbutyrate. Add 16 parts of paradichlorobenzene (PDCB)
5.1 kg (1.123 kmole) is charged, and further, 583 kg (0.32 kmol) of pure water is charged, and 210 ° C.
For 3 hours. The reaction solution was cooled to 60 ° C. or lower, and the reaction mixture was withdrawn from the reactor into a 20 L container. The conversion of PDCB was 85%.

Continuous Main Polymerization Main polymerization was carried out using a polymerization tank shown in FIG. 1A. That is, a 10-liter autoclave equipped with an extraction line with an inner diameter of 4 mm at the center of the bottom of the head plate, a baffle and a liquid level gauge on the wall surface, and a full-zone blade as a stirring blade (the clearance between the full-zone blade tip and the bottom is 10 mm). 855 g of lithium chloride and 5145 g of NMP were charged as a separating agent, the temperature was raised to 260 ° C., the prepolymer obtained in the preliminary polymerization was maintained at 60 ° C., and was continuously supplied at a rate of 45 g / min using a gear pump. The rotation speed of the stirring blade was 140 rpm (0.2 kW / m ³ ). on the other hand,
By controlling the liquid level gauge and a valve provided in the extraction line, the polymer phase was continuously extracted from the extraction line at the bottom center so that the liquid level was constant. The liquid extracted from the sample line located at the center of the liquid depth (in which the polymer phase and the solvent phase are dispersed) was cooled, and after observing the dispersion state of the polymer phase with a microscope, a spherical polymer was observed. It was found that the dispersion state in the tank was good.

Example 2 The same procedure as in Example 1 was carried out except that the one shown in FIG. 1B was used as a continuous polymerization tank, that is, the tip of the extraction line (extraction port) was protruded into the tank 5 mm from the bottom of the end plate. The operation was performed. Similarly, when the dispersion state of the polymer phase was observed, a spherical polymer was observed, and it was found that the dispersion state in the polymerization tank was good. Comparative Example 1 The same operation as in Example 1 was performed except that the one shown in FIG. 2 was used as the continuous polymerization tank, that is, the extraction line was provided at a position 100 mm higher than the lower tangent line of the polymerization tank. Similarly, when the dispersion state of the polymer phase was observed, an amorphous polymer was observed, and it was found that the dispersion state in the polymerization tank was poor.

[0021]

According to the present invention, a PAS production method capable of forming a uniform dispersion state of a polymer phase in a PAS polymerization tank and controlling the composition ratio of a polymer and a solvent more accurately, and a simple specification. Thus, it is possible to provide a PAS manufacturing apparatus capable of forming a uniform dispersion state and controlling the composition ratio of the polymer and the solvent with higher precision.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing one example of a manufacturing apparatus of the present invention.

FIG. 2 is a schematic sectional view showing an example of a manufacturing apparatus outside the present invention.

[Explanation of symbols]

 1: polymerization tank 2: stirring blade 3: baffle 4: end plate 5: extraction part

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 4J030 BA03 BB21 BC02 BD21 BF09 BF13 BF15 BG04

Claims (4)

[Claims] 1. A method for producing polyarylene sulfide in which a polyarylene sulfide is polymerized in a polymerization tank to separate into a polymer phase and a solvent phase, wherein the polymer phase is extracted from an extraction portion provided on a head plate of the polymerization tank. For producing polyarylene sulfide. 2. The method according to claim 1, wherein the extraction section is provided at the bottom of the polymerization tank. 3. The method according to claim 1, wherein the withdrawing portion projects from the bottom of the polymerization tank into the polymerization tank. 4. An apparatus for producing a polyarylene sulfide having a polymerization tank provided with a stirring blade, wherein 0 to 80% of a gap distance between a tip of the stirring blade and a bottom of the polymerization tank is provided on a head plate of the polymerization tank. An apparatus for producing polyarylene sulfide, comprising a withdrawal portion having a length protruding into a polymerization tank.